Dear Editor,

We read the article entitled “management of menopause in women with a history of endometriosis” by Akgün et al. (1) with a great deal of interest. The authors discussed the hormone replacement therapy (HRT) options, indications, and contraindications in postmenopausal patients with endometriosis. Furthermore, a recently published prospective cohort study examined the relationship between endometriosis and fibroids and the risk of premature mortality, highlighting the importance for primary care providers to consider these gynecological disorders in their assessment of women’s health (2). Barnard et al. (3) investigated the relationship between endometriosis typology and ovarian cancer risk. Ovarian cancer risk was highest in women with deep infiltrating endometriosis and/or ovarian endometriomas for all ovarian cancers. These authors recommended counseling regarding ovarian cancer risk and prevention (3).

As mentioned by Akgün et al. (1), endometriosis is a hormone-dependent condition and residual or recurrent endometriotic lesions might still be found in menopause. In this scenario, we would like to ask whether HRT might increase the risk of malignancy. A recent meta-analysis reported that the risk of ovarian malignancy, especially for serous histological type, increased with prolonged exposure time, especially when estrogen replacement therapy (ERT) exceeded 10 years. In the same meta-analysis, it was recommended that long-time users should consider continuous estrogen-progesterone replacement therapy (EPRT) as a safer alternative (4).

Moreover, Lee et al. (5) analyzed a database of ten cancers (cervical, uterine, ovarian, breast, colon, stomach, liver, lung, pancreas, and thyroid) and showed that HRT was a significant risk factor for uterine cancer, but decreased the risk of liver and thyroid cancer while ERT decreased the risks of breast and lung cancers significantly. In the same study, tibolone was not associated with the risk of any of the cancers assessed. Finally, the same group of researchers clarified in another meta-analysis that, although the use of ERT was found to be a significant risk factor for ovarian cancer, after adjusting for co-variables, HRT use, duration of HRT, EPRT and tibolone were not found to be associated with increased risk of developing ovarian cancer (6). The practical implications for clinical decision-making and a clearer differentiation of risks associated with ERT, EPRT, and tibolone would further enhance its impact.